Mixed polyvinyl esters containing dicarboxylic acid groups



' Patented Mar. 10, 1942 MIXED POLYVINYL ESTERS CONTAINING DICARBOXYLICACID GROUPS Martti Salo, Rochester, N. Y., assignor to- Eastman KodakCompany, Rochester, N. Y., a corporation of New Jersey No Drawing.Application March 21, 1940, Serial No. 325,185. In Great Britain April6, 1939 7 Claims.

This invention relates to mixed polyvinyl esters containing lower fattyacid groups and dicarboxylic acid groups, and their preparation.

In producing photographic materials it is often desirable to employcoatings which are readily soluble in alkalies so that these materialsare present initially but are removed in the developing baths used inprocessing. Various materials which are alkali soluble and useful forcoatings are known but due to the expense involved in their preparationthey are used only sparingly. An object of my'invention is to providealkalisoluble material which can be readily coated out as a layer ontophotographic film but which may be dissolved oil by treating the filmwith alkali. Another object of my invention is to provide a method ofmaking materials of this type which is inexpensive and easily carriedout. A further object of my invention is to provide a method of makingdicarboxylic acid esters of polyvinyl compounds in which the use ofpyridine or other organic base is unnecessary.

My invention in its broadest aspects comprises the treatment of a lowerfatty acid ester of polyvinyl alcohol with a dicarboxylic acidanhydride,

\ in an inert solvent containing a little water, at a moderatelyelevated temperature. I have found that the polyvinyl ester of a lowerfatty acid can be readily esterifled, taking on dicarboxylic acid groupsin this manner.

Any of the lower fatty acid esters of polyvinyl alcohol may be used asthe starting material of my process. For instance, polyvinyl acetate hasbeen found suitable but the propionate or butyrate may be employed, ifdesired, or the mixed esters, such as the acetate propionates andacetate butyrates, might be used. As the. higher viscosity polymersintroduce difliculties in carrying out the reaction, the low and mediumvis- --cosity polyvinyl esters are most useful as the starting material.For example, with the polyvinyl acetates, those having a viscositywithin the range of 2-60 0. p. s. are the most useful. The polyvinylesters, which areemployed as the start- .ing material. may be eitherfully esterifled or partially hydrolyzed materials. With the use ofpartially hydrolyzed polyvinyl esters or those containing hydroxylgroups, the amount of water employed need not be as great as with acorresponding process using fully esterifled polyvinyl acetate.

The anhydride employed in my process should be the anhydride of adicarboxylic acid in which the carbons of the two carboxyls are Joinedby one or more carbons or other atoms. Examples of acids of this typeare phthalic, succinic, glutaric, diglycolic and maleic. In most casesthe carboxyls are joined by intermediate carbon linkages.

The solvent, which is employed, may be any solvent which has thefollowing characteristics: 1. At least moderately miscible with water.

2. Chemically stable.

3. A solvent for the starting materials and for the final product.

I have found that the mostl suitable solvents of this nature are thelower aliphatic ketones, such as acetone, and -methyl ethyl ketone.Although the amount of solvent which is employed is not critical, Iprefer to employ at least one part of solvent to one part of polyvinylester. Ordinarily, an amount of solvent within the range of 1 to 2 partsper part of polyvinyl ester is suflicient. The practical limits oftemperature range for this reaction are between about 250-350 F. Areaction temperature within this range is ordinarily suitable. Thepractical limits of the range of time within which this reaction shouldbe carried out is 5-20 hours. Increasing the time beyond this rangeserves no useful purpose. Under good working conditions, a time withinthe range of 5-8 hours is usually suflicient to obtain the desiredreaction product.

The alkali solubility of the product obtained depends upon the amount ofdicarboxylic acid ester groups introduced into the resin. This isgoverned by two factors, the proportion of phthalic anhydride and theproportion of water. In order to obtain alkali solubility, theproportion of phthalic anhydride used should be at least .75 part perpart of polyvinyl ester. An amount of phthalic anhydride within therange of .75 to 1.25 parts per part of the polyvinyl ester has beenfound to be most satisfactory in my process. The proportion of watershould be at least 0.05 part per part of polyvinyl ester to obtainalkali solubility. With an increase of the amount of phthalic anhydrideand the amount of water, the amount of phthalyl introduced into theresin will be increased. However, if only one of these ingredients isincreased in proportion without the other, the proportion of phthalylintroduced is not affected. If only the amount of water is increased,hydrolysis off of some of the acyl content in preparing my product willresult without any added taking on of dicarboxylic acid groups. I havefound that the best range for content of water in processes inaccordance with my invention are 0.05 to 0.2 part for every one part ofpolyvinyl ester. By the means described,

' equipped with a stirring device.

- perature.

an alkali-soluble product is obtained; In order to be alkali soluble thephthalates must have a content of at least 15-20% combined phthalyl.

A formula, which I have found works very sat- With the lower boilingsolvents an autoclave or refiuxingshould be used to avoid loss ofsolvent. The following examples illustrate my invention:

Example I 400 parts of fully esterified polyvinyl acetate, having aviscosity of 7 c; p. s., was dispersed in 400 parts of methyl ethylketone in arr-autoclave There was then added with stirring, 400 parts ofphthalic anhydride and 43 parts of water. The autoclave was closed, thestirrer was set in motion andthe temperature of the reaction mixture wasraised to 280-290" F. After stirring for five hours at this temperature,the mass was cooled to room temperature, diluted with approximately tenvolumes of 70:30 acetone-water mixture. The product was precipitatedinto water at room temperature, washed, centrifuged and dried, at a lowtem- The product, which was soluble in a number of organic solvents andin dilute alkalies, had an acetyl content of 29.6% and a phthalylcontent'of 26.7%. It was found also to have a viscosity of 5 c. p. s. at25 C. in a solution of 55:45 by weight ethyl alcohol-acetone mixture.

4 Example 11- The procedure of the above example was re-- peated exceptthat80 parts of water was used and the reaction was run for 6 hours inan autoclave at a temperature of approximately 300 F. The

resulting product was found to be soluble in a number of organicsolvents and. also in dilute aqueous alkali.

Example III a 75 pounds of, fully esterifled polyvinyl acetate, having aviscosity of 25 c. p. s., was dissolved in 75 pounds of methyl ethylketone in a 75 gallon steam-heated reaction vessel. 75 pounds ofphthalic anhydride and 7.5 pounds of distilled rapidly as possible. Themixture was agitated for 7 hours with the temperature of the mixturekept between290 and 302 F. Tests made on smallsamples showed that theproduct reached solubility in 3% aqueous sodium hydroxide inabout 6%hours. Thevessel was cooled to room temperature and emptied. The productwas precipitated in water with violent agitation and washed thoroughlywith cold water and then with hot water. The product was dried at room.temperature and was found to have a phthalyl content of 19.2% and anacetyl content of 32.5%.

Example IV then cooled to room temperature, diluted with approximately10 volumes of a 70:30 acetonewater mixture and precipitated in water atroom temperature. ing, an enclosed reaction vessel such as an autoclaveor refluxing vessel was not necessary as the temperature employed didnot drive off any appreciable amount of the acetonyl acetone.

The dicarboxylic acid esters of polyvinyl alcohol of my invention may becombined with bases, either organic or inorganic, to form salts. For

' instance, a polyvinyl acetate phthalate or polysalts may be preparedby a double-decomposition water was added thereto. The reaction vesselwas closed and the temperature was raised as vinyl acetate succinate ofmy invention may be mixed with an aqueous solution of an alkali metalcarbonate, such as sodium bicarbonate, to form awater-soluble alkalimetal salt. Heavy metal reaction of the alkali metal salt with awatersoluble salt of the heavy metal. For instance, the sodium salt ofpolyvinyl acetate phthalate may be combined with copper sulfate inaqueous solution to form the copper salt of the polyvinyl acetatephthalate. The polyvinyl ester in accordance with my invention may alsobe combined with ammonia or a. substituted ammonia such as ethyl amineor an ethanolamine to form the corresponding water-soluble salt.

The esters which I have described herein, are desirable aslayers onphotographic film; for instance, for anti-halation backings, or thelike, when mixed with a small proportion of a dye, such as a blue orblack dye, which will overcome halation. This backing, dueto its alkalisolubility. will be dissolved by a conventional type of developing bath,thus leaving a transparent negative. They are also useful in any othercases where a temporary resin coating is desired,

The viscosity of polyvinyl acetate, referred to herein, is' theviscosity in centipoises at 20 C. of a solution containing 8.6 gmsoftate in 10000. of benzene.

' I claim:

1. The process of preparing a polyvinyl ester containing lower fattyacid and dicarboxylic acid,

groups which comprises reacting together approximately one'part of 'apolyvinyl ester of a fatty acid of 2-4 carbon atoms, approximately.75-1.25 parts of a dicarboxylic acid anhydride and approximately0.05-0.2 part of water in approximately 1-2 parts of an inert,water-miscible solvent for the starting materials and the polyvinylester prepared, at a temperature within the range 01' 250-350 F.

2. The process of preparing a polyvinyl ester containing lower fattyacid and dicarboxylic acid groups which comprises reacting togetherapproximately one part of a polyvinyl ester of a fatty acid of 2-4carbon atoms, one part of a dicarboxyllc acid anhydride and 0.1 part ofwater in approximately 1-2 parts of an inert watermiscible solvent forthe starting materials and the polyvinyl ester prepared, at atemperature within the range of 250-350" F.

- 3. The process of preparing a polyvinyl ester containing lower fattyacid and phthalyl groups which comprises reacting together approximatelyone part of a polyvinyl ester of a fatty acid of 2-4 carbon atoms,approximately .75-1.25 parts of phthalic anhydride and approximately0.05-0.2 part of water in approximately 1-2 parts of an inertwater-miscible solvent for the starting materials and the polyvinylester prepared,'at a temperature within the range of 250-350 F.

4. The process of preparing alpolyvinyl ester containing lower fattyacid and succinyl groups As the solvent used was high boilpolyvinyl Iacewhich comprises reacting together approximately one part of apolyvinyl ester of a fatty acid 012-4 carbon atoms, approximately175-125 parts of succinic anhydride and approximately 0.05-0.2 part ofwater in approximately 1-2 parts of an inert water-miscible solvent forthe starting materials and the polyvinyl ester prepared, at atemperature within the range of250-350.

5. The process of preparing a polyvinyl ester containing acetyl anddicarboxylic acid groups which comprises reacting together approximatelyone part of polyvinyl acetate, approximately .75- 1.25 parts of adicarboxylic acid anhydride and approximately 0.05-0.2 part of water inapproxi- 1-2 parts of an inert water-miscible solvent for the startingmaterials and the polyvinyl ester prepared, at a temperature within therange of 250-350 F.

proximately one part of polyvinyl acetate,'approximately 315-125 partsof phthalic anhydride and approximately 0.05-0.2 part of water inapproximately 1-2 parts of'methyl ethyl ketone, at a temperature withinthe range or 250-350 F. 7. The process of preparing a polyvinyl estercontaining lower fatty acid and dicarboxylic acid groups which comprisesreacting together approximately one part of a polyvinyl ester of a fattyacid of 2-4 carbon atoms, one part of a dicarboxylic acid anhydride and0.1 part. of water in approximately 1-2 parts of methyl ethyl ketone, ata temperature within the range of 250 350 F. s p i t MAR'I'II SALO.

6. The process of preparing a'polyvinyl acetate phthalate whichcomprises reacting together ap-

